Who would have thought that the secret to securing Selena Gomez's affections would be to act out? Justin Bieber took time from his busy schedule of threatening paparazzi, tussling with his neighbors, abandoning his monkey and making Anne Frank's plight all about him to reunite with his ex-girlfriend in Norway.

On Thursday, the starlet, 20, jetted to Oslo for a rendezvous with the misbehaving pop star, 19, who was performing in town on his world tour.

"They were holding hands, hugging and they kissed on the lips," an eyewitness tells People. "They looked really in love, like no fights ever happened before. It definitely looked like they were back together."

But the pair, who began dating in late 2010, have indeed had plenty of the aforementioned fights. In addition to a reportedly relationship-ending blowout in Puerto Vallarta, Mexico, just before New Year's, they also had a very public tiff at a Los Angeles restaurant in November.

A month ago, Selena confirmed to David Letterman that she was single and "so good," and even worked in a zinger about making her former flame cry.

The Biebs, who paid a brief visit to Gomez a few weeks back, appears to be carrying the modern version of a torch. TMZ noticed his iPhone screen features a glamour shot of Gomez from a recent photo shoot.

It looks like she wasn't put off by his camp's claims that his recent spate of bad behavior was her fault. Seems he felt "tortured" by her "mixed messages," and it's been "messing with his head."

"They have a crazy connection," a source tells Us Weekly. "They just can't seem to break their connection. It can be intense."

We're sure that intensity is comforting to Justin's monkey, who remains in quarantine in Germany. Anyhoodie, click on for oodles more pictures of Jelena's PDA, including the cuddly photo he shared then quickly deleted on Saturday ...